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A muscle, seated on the lateral parts of the lumbar portion of the vertebral column; and passing down to the superior and anterior part of the thigh. It is long, fusiform, and attached, above, to the body and transverse processes of the first four lumbar vertebrae, and last dorsal. Below, it terminates, by a very thick tendon, common to it and the iliacus muscle, - which is inserted into the top of the lesser trochanter. This muscle bends the thigh upon the pelvis, and carries it in rotation outwards. It may, also, bend the pelvis on the thigh, and the loins on the pelvis. It acts considerably in station and progression.